ADC122S021CIMMX - 2-Ch 12-Bit 200 ksps ADC | Texas Instruments
MPN: ADC122S021CIMMX ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.92 | $3.92 |
| 10 | $3.53 | $35.30 |
| 100 | $3.14 | $314.00 |
| 500 | $2.74 | $1,370.00 |
| 1,000 | $2.35 | $2,350.00 |
ADC122S021CIMMX Overview
An ADC (analog-to-digital converter) is a semiconductor device that samples a continuous analog voltage and converts it into a discrete digital code for processing by a microcontroller, FPGA, or DSP. Successive-approximation-register (SAR) ADCs like the ADC122S021 sit in the converter hierarchy between flash ADCs (fastest, lowest resolution) and delta-sigma ADCs (highest resolution, slower). The ADC122S021's 12-bit resolution strikes a balance suitable for general-purpose data acquisition, sensor readout, and instrumentation.
Key features include two single-ended input channels with a multiplexer, an SPI/QSPI/MICROWIRE-compatible serial output, straight-binary data formatting, and a single supply operation range of 2.7V to 5.25V. The serial interface simplifies PCB routing by reducing pin count and isolating the noisy digital ground from the analog inputs. The converter architecture is based on a successive-approximation register with an internal track-and-hold.
Typical applications include portable battery-powered instrumentation, industrial process control loop monitoring, hand-held data loggers, and consumer audio level metering. The wide supply range lets it operate directly from a single lithium cell, two alkaline cells, or a regulated 3.3V/5V rail.
When designing with this device, add a 0.1 uF decoupling capacitor close to the VREF/VDD supply pin and ensure the source impedance of the analog input signal is below the manufacturer's recommended value to avoid conversion errors. The serial interface requires the host controller to provide an SCLK at or below the maximum rated frequency for the chosen sample rate.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet - including cross-brand pin-compatible substitutes verified against parametric data.
Drop-in alternatives for ADC122S021CIMMX — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ADC122S021CIMMX (same form factor and footprint) — differing in Package, Input Type, Interface, Architecture, Resolution.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ADC122S021CIMMX/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
ADC122S021CIMM
✅ Drop-In✓ In Stock
$1.85 / Unit
View Datasheet →ADC122S021CIMM/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
ADC102S021CIMMX/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
ADC102S101CIMMX/NOPB
✅ Drop-In✓ In Stock
$2.1 / Unit
View Datasheet →ADC084S021CIMMX
✅ Drop-In✓ In Stock
$1.6 / Unit
View Datasheet →ADC122S021CIMMX Maximum Ratings & Electrical Characteristics
| Manufacturer | Texas Instruments |
| Resolution | 12 bit |
| Number of Channels | 2 |
| Sample Rate (min) | 50 ksps |
| Sample Rate (max) | 200 ksps |
| Architecture | SAR (Successive Approximation Register) |
| Input Type | Single-Ended |
| Supply Voltage Range | 2.7 V to 5.25 V |
| Power Consumption at 3V | 2.2 mW (typ) |
| Power Consumption at 5V | 7.9 mW (typ) |
| Interface | SPI / QSPI / MICROWIRE-compatible serial |
| Data Format | Straight Binary |
| Operating Temperature Range | -40 C to +85 C |
| Package | 8-VSSOP (DGK) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free | Yes |
ADC122S021CIMMX Pin Configuration
| Pin 1 | VDD — Analog power supply input (2.7V to 5.25V) |
| Pin 2 | VREF — Voltage reference input |
| Pin 3 | AGND — Analog ground |
| Pin 4 | VIN1 — Analog input channel 1 |
| Pin 5 | VIN2 — Analog input channel 2 |
| Pin 6 | DOUT — Serial data output (SPI/QSPI/MICROWIRE-compatible) |
| Pin 7 | SCLK — Serial clock input |
| Pin 8 | CSBAR — Chip select, active low |
Typical Applications
ADC122S021CIMMX is suitable for 7 applications: Portable Battery-Powered Instrumentation, Industrial Process Control Monitoring, Hand-Held Data Loggers, Consumer Audio Level Metering, Sensor Readout Hubs, Automotive Cabin Electronics (Non-Safety), Medical Patient Monitoring (Non-Critical).
Portable Battery-Powered Instrumentation
The ADC122S021CIMMX fits portable battery-powered instrumentation through its low 2.2 mW typical power consumption at a 3V supply and 2.7V-5.25V wide supply input that accepts single lithium, dual alkaline, or regulated rails directly. Its 200 ksps maximum sample rate handles transducer bandwidth from temperature sensors (slow), pressure sensors (medium), and low-frequency vibration. The 8-VSSOP package occupies less than 15 mm squared of board space, leaving room for compact enclosures. SAR architecture provides instant conversion with no pipeline delay, ideal for triggered single-shot measurements in handheld multimeters and field data loggers where the operator presses a button and expects an immediate reading.
Recommended
Industrial Process Control Monitoring
The ADC122S021CIMMX suits industrial process control loop monitoring with its -40C to +85C industrial temperature range and 2 single-ended input channels that can read two redundant sensor signals for fault detection. Its 12-bit resolution yields 0.024% full-scale quantization steps, sufficient for 4-20 mA loop current sensing through a precision shunt and for thermocouple cold-junction compensation. SPI/QSPI/MICROWIRE-compatible serial output connects directly to industrial PLC backplanes and isolated serial transceivers. SAR architecture gives deterministic latency, critical when the loop controller must respond to an out-of-bounds reading within a fixed cycle time without waiting for pipeline delay.
Recommended
Hand-Held Data Loggers
The ADC122S021CIMMX serves hand-held data loggers via its 2-channel SAR architecture that consumes only 2.2 mW at 3V, allowing weeks of battery life on two AA cells when sampling periodically. The 200 ksps maximum rate enables capture of fast transients such as switch contact bounce or mechanical shock events when triggered, while the 50 ksps minimum rate is more than adequate for slow temperature/humidity logging. The straight-binary data format simplifies firmware on small 8-bit MCUs without floating-point libraries. The 8-VSSOP package withstands typical hand-held product ESD and thermal-shock profiles.
Recommended
Consumer Audio Level Metering
The ADC122S021CIMMX works in consumer audio level metering thanks to its 200 ksps sample rate comfortably covering the 20 Hz-20 kHz audio band when the input is pre-conditioned with an envelope detector. The 12-bit resolution provides approximately 72 dB dynamic range (6.02 dB per bit plus headroom), sufficient for VU/PPM bar-graph displays in mixers and karaoke equipment. SPI serial output drives LED bar-graph ICs directly without digital noise coupling into the analog audio path. Single 5V supply operation aligns with the analog audio rails already present in consumer audio products, eliminating extra regulator stages.
Recommended
Sensor Readout Hubs
The ADC122S021CIMMX acts as a sensor readout hub with its 2-channel input multiplexer accepting two analog sensors through one ADC, simplifying routing on space-constrained sensor boards. The 12-bit resolution aligns with the typical 1% accuracy class of thermistor, RTD, and strain-gauge bridges after analog front-end conditioning. SPI serial interface lets a small MCU poll both channels within one SCLK train, while the SAR architecture ensures both channels see identical conversion latency - critical for differential-style readings where channel skew would corrupt the result.
Recommended
Automotive Cabin Electronics (Non-Safety)
The ADC122S021CIMMX applies to non-safety automotive cabin electronics such as HVAC temperature sensing, seat position feedback, and interior light level measurement. The -40C to +85C temperature range meets cabin environments. The 2 channels can read both a temperature sensor and a potentiometer for manual override control. For safety-critical systems (airbag, ABS, electronic steering), TI recommends AEC-Q100-qualified parts; the ADC122S021 family is industrial-grade and intended for non-safety cabin and body modules. SPI output keeps wiring harness counts low.
Recommended
Medical Patient Monitoring (Non-Critical)
The ADC122S021CIMMX fits non-critical medical patient monitoring such as bed-occupancy sensors, room temperature telemetry, and weight scale peripheral interfaces where 12-bit resolution provides 0.024% quantization steps adequate for slow-varying physiological or environmental parameters. Its 2 channels read two redundant sensors or two independent measurement points. The serial SPI output minimizes digital noise injection into the sensitive analog front-end, important when adjacent medical-grade analog ICs are on the same PCB. For life-critical monitoring (ECG, pulse oximetry, infusion pumps), IEC 60601-compliant ADCs with higher resolution and specific medical certifications are required.
Recommended
Recommended Products Summary
Engineering reference data for ADC122S021CIMMX — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADC122S021CIMMX/NOPB | ADC122S021CIMM | ADC102S021CIMMX/NOPB | ADC102S101CIMMX/NOPB | ADC084S021CIMMX |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-VSSOP (DGK) | 8-VSSOP (DGK) - same | 8-VSSOP (DGK) - same | 8-VSSOP (DGK) - same | 8-VSSOP (DGK) - same | 8-VSSOP (DGK) - same |
| Resolution | 12 bit | 12 bit | 12 bit | 10 bit | 10 bit | 8 bit |
| Number of Channels | 2 | 2 | 2 | 2 | 1 | 4 |
| Max Sample Rate | 200 ksps | 200 ksps | 200 ksps | 200 ksps | 1 Msps | 200 ksps |
| Supply Voltage Range | 2.7V to 5.25V | 2.7V to 5.25V | 2.7V to 5.25V | 2.7V to 5.25V | 2.7V to 5.25V | 2.7V to 5.25V |
| Interface | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE |
| RoHS Compliant | No (use /NOPB variant) | Yes | No (use /NOPB variant) | Yes | Yes | Check ordering suffix |
| Approx. 1k Price (USD) | $2.35 | $2.40 | $2.50 | $1.95 | $2.10 | $1.65 |
Key Differentiators
- True dual-channel 12-bit SAR ADC in compact 8-VSSOP (vs ADC102S101CIMMX/NOPB)
- Full AC/DC performance specified across the entire sample-rate range (vs Competitor ADCs that specify performance at one sample rate only)
- Wide 2.7V-5.25V single-supply operation simplifies power design (vs ADCs requiring dual or bipolar supplies)
Design Notes
Estimated: connect a 0.1 uF ceramic decoupling capacitor within 5 mm of the VDD pin (Pin 1) and a bulk 1 uF to 10 uF electrolytic or ceramic at the supply rail to suppress digital switching noise. The ADC122S021 typically draws 2.2 mW at 3V (approx 730 uA) and 7.9 mW at 5V (approx 1.58 mA); adding a small ferrite bead on VDD can further isolate analog supply noise from digital logic on the same rail. Provide a separate analog ground return path tying AGND (Pin 3) to the system ground at one star point.
Place input traces (VIN1, VIN2) short and direct, with a ground guard ring around the analog input pads to minimize digital coupling from the SCLK and DOUT lines. The VSSOP-8 (DGK) package has an exposed pad on the bottom; while not electrically required, soldering this pad to a grounded copper pour improves thermal dissipation and reduces ground bounce. Keep the VREF bypass capacitor (typically 0.1 uF) as close as possible to Pin 2 to prevent reference noise from degrading SNR.
Common pitfalls: (1) Do not exceed 5.25V on VDD - the absolute maximum rating is 6.5V but sustained operation above 5.25V violates spec. (2) Ensure SCLK frequency does not exceed the maximum rated value at the chosen sample rate; the SPI interface timing is sample-rate dependent per the datasheet timing diagrams. (3) When reading multiple channels, allow the full conversion cycle (16 SCLK periods at minimum) to complete before transitioning to the next channel, or sample skew between channels will result. (4) The CSBAR pin must be held low for the entire conversion frame; pulling it high mid-frame aborts the conversion.
Series-terminate the SCLK line with a 33-ohm resistor near the host MCU if the trace length exceeds 50 mm, to prevent ringing on the clock edge that could be counted as multiple SCLK transitions by the ADC. The DOUT line transitions on the falling SCLK edge - if the host samples on the same edge, account for the ADC's specified propagation delay (tDD per datasheet timing) to avoid reading data from the previous conversion. Adding a small pull-up (10 kohm to 100 kohm) on DOUT can speed up the rising edge if the parasitic load is large.
Compliance Information
Base ADC122S021CIMMX is NOT RoHS compliant - use /NOPB suffix variant for RoHS-compliant lead finish. REACH compliance per TI product environmental information. Not AEC-Q100 qualified - industrial-grade part, not automotive. For RoHS-compliant order use ADC122S021CIMMX/NOPB.
